Published online by Cambridge University Press: 17 November 2015
Herbivores are predicted to forage on a variety of plants in order to obtain a nutritionally sufficient diet. Most herbivores, however, forage non-randomly and may be influenced by morphological, chemical and physical traits in their food. We examined the influence of several leaf traits on food selection for the Exuma rock iguana (Cyclura cychlura figginsi). We expected the iguana to prefer leaves with higher nutrient concentration and lower physical defences, such as reflected by high N, P, Ca, K, Mg concentrations and low leaf density and per cent concentrations of cellulose, hemicellulose and lignin, respectively. We quantified selection by examining 30 faecal samples and analysing traits of leaves from the 10 most common plants on the island. Our results showed substantial variability in all measured traits among species but food preference only for less-dense leaves, a good indicator of low leaf toughness. Our results are the first to demonstrate that physical leaf traits can influence food selection in a true herbivorous lizard and offer a basis for future testing.